Ruby script for file conversion displays error 'getbit': undefined method'

I'm a programmer and not the developer of the Ruby script for questions.

When I try to use the Ruby script for file format conversion, I get an error and stop halfway.

I'm trying to convert dictionary data to EPWING so that I can use my dictionary software on my smartphone/tablet, but when I try to convert it to text with Ruby script, I get the following error:

C:/work/BTONIX2xml.rb:57in'getbit': undefined method'>'for"\xF0": String(NoMethodError)

I thought the script was 10 years old, so I tried it in various versions and environments, but I couldn't solve it by myself.The environment I tried was Ruby 1.8x, 1.9x, 2.0x, 2.2x installed with Windows 7 32-bit and 64-bit RubyInstaller.

By the way, here's the command I used:

ruby-Ks C:\work\BTONIC2xml.rb "C:\Program Files
(x86)\(Dictionary software folder)\(Dictionary name)\(Dictionary name).xi"C:\btonic

I came here thinking that I might be able to modify some of the code in the script.

I would be very grateful if someone could tell me something. m(__)m